Summary:
This is a result of the discussion at D78113. Previously we would be
only giving the current offset at which the error was detected. However,
this was phrased somewhat ambiguously (as it could also mean that end of
data was at that offset). The new error message includes the current
offset as well as the extent of the data being read.
I've changed a couple of file-level static functions into private member
functions in order to avoid passing a bunch of new arguments everywhere.
Reviewers: dblaikie, jhenderson
Subscribers: hiraditya, MaskRay, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78558
Summary:
This constructor allows us to create a new DWARFDataExtractor which will
only present a subrange of an entire debug section. Since debug sections
typically consist of multiple contributions, it is expected that one
will create a new data extractor for each contribution in order to
avoid unexpectedly running off into the next one.
This is very useful for unifying the flows for detecting parse errors.
Without it, the code needs to consider two very different scenarios:
1. If there is another contribution after the current one, the
DataExtractor functions will just start reading from there. This is
detectable by comparing the current offset against the known
end-of-contribution offset.
2. If this is the last contribution, the data extractor will just start
returning zeroes (or other default values). This situation can *not*
be detected by checking the parsing offset, as this will not be
advanced in case of errors.
Using a truncated data extractor simplifies the code (and reduces
cognitive load) by making these two cases behave identically -- a
running off the end of a contribution will _always_ produce an EOF error
(if one uses error-aware parsing methods) or return default values.
Reviewers: dblaikie, probinson, jhenderson, ikudrin
Subscribers: aprantl, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77556
Summary:
If we have an (invalid) relocation which relocates bytes which partially
lie outside the range of the relocated section, the getRelocatedValue
would return confusing results. It would first read zero (because that's
what the underlying DataExtractor api does for out-of-bounds reads), and
then relocate that zero anyway.
A more appropriate behavior is to return zero straight away. This is
what this patch does.
Reviewers: dblaikie, jhenderson
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78113
Summary: Include the offset at which this happened.
Reviewers: dblaikie, jhenderson
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75265
Summary:
This patch introduces a function to house the code needed to do the
DWARF64 detection dance. The function decodes the initial length field
and returns it as a pair containing the actual length, and the DWARF
encoding.
This patch does _not_ attempt to handle the problem of detecting lengths
which extend past the size of the section, or cases when reads of a
single contribution accidentally escape beyond its specified length, but
I think it's useful in its own right.
Reviewers: dblaikie, jhenderson, ikudrin
Subscribers: hiraditya, probinson, aprantl, JDevlieghere, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74560
Pavel Labath